JPH0395505A - Manufacture of optical fiber - Google Patents

Abstract

PURPOSE:To manufacture the optical fiber with a uniform external diameter continuously by controlling a tension roller according to a measured value of an external diameter measuring instrument, and controlling a take-up speed so that the tension becomes constant. CONSTITUTION:A clad material 3 made of a rubber material is extruded from a double concentric circular extrusion nozzle 4 simultaneously with a core material 2 made of a rubber material to form the optical fiber 1. At such a time, the external diameter measuring instrument 7 measures the external diameter of the optical fiber, and the tension roller 9 is controlled through a control member 11 to obtain a desired measured value, thereby determining the tension which operates on the optical fiber 1. The take-up speed of a take-up machine 10 is so controlled that the determined tension is maintained. Consequently, the rubbery elastic optical fiber which has specific external diameter with small variance can be manufactured continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing an optical fiber, and particularly to a method of manufacturing a rubber-like elastic optical fiber having a constant outer diameter.

[Prior Art and Problems to be Solved] Conventionally, there has been a manufacturing technology for a rubber-like elastic optical fiber in which a core made of a rubber-like elastic material having a three-dimensional network structure is coated with a cladding made of a rubber-like elastic material having a three-dimensional network structure. , Japanese Patent Publication No. 61-259
No. 202 and Japanese Unexamined Patent Publication No. 64-503, etc., however, there is no mention of methods for controlling the dimensions of optical fibers, processing after extrusion (for example, winding), etc.

Generally, in the manufacturing process of rubber-like elastic optical fiber,
Compared to optical fibers made of quartz or plastic, which are hard at room temperature, it is extremely difficult to control their dimensions because they are cast under their own weight before the crosslinking reaction occurs after extrusion.

In addition, the polymer materials used for the core material and cladding material of rubber-like elastic optical fibers are manufactured at different lofts, and each loft has completely the same physical properties (extrusion viscosity, etc.). isn't it.

Therefore, if the loft of the polymeric material supplied for the core material and cladding material of the rubbery elastic optical fiber changes, the extrusion viscosity will differ even with the same extrusion pressure, and the diameter of the rubbery elastic optical fiber immediately after extrusion will change. However, it has been extremely difficult to manufacture rubber-like elastic optical fibers having uniform outer diameter dimensions.

The present invention solves the problems of the conventional methods as described above, and provides an optical fiber manufacturing method that can continuously manufacture rubber-like elastic optical fibers having a uniform outer diameter. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention extrudes a rubber core material from a double concentric extrusion nozzle, and also extrudes a rubber cladding material covering the outer periphery of the rubber core material. A method for manufacturing an optical fiber, in which an optical fiber obtained by simultaneous extrusion and crosslinking treatment is wound in a winder, the optical fiber being driven by a control member at a predetermined winding speed. At the same time, the control member operates the tension roller to apply a predetermined tension to the optical fiber, and then the measured value of the outer diameter measuring member that measures the outer diameter of the optical fiber is measured. , the control member controls the tension roller to determine the tension acting on the optical fiber so as to obtain a desired outer diameter dimension, and then the control member controls the winding to maintain the determined tension. It has means for controlling the winding speed of the machine.

[Effect]

By employing the above-mentioned means, the present invention applies tension to the optical fiber in the manufacturing process using a tension roller so that the outer diameter of the optical fiber becomes a predetermined dimension at the time of winding, and furthermore, the tension is kept constant. Since the winding speed of the winder is controlled by the control member so that the winding speed is maintained, the outer diameter of the resulting optical fiber can be a desired dimension and constant.

[Specific structure of invention]

The present invention will be explained in detail below.

FIG. 1 shows a schematic diagram illustrating the method of manufacturing an optical fiber according to the present invention, and FIG. 2 shows the main parts thereof.

That is, first, the rubber core material 2 is loaded into the inner nozzle of the double concentric extrusion nozzle 4, and the rubber cladding material 3 is loaded into the outer nozzle of the double concentric extrusion nozzle 4.
Core material 2 and cladding material 3 are simultaneously extruded from double concentric extrusion nozzle 4.

Then, the extruded raw optical fiber is sent into a lamp house 5 equipped with a high-pressure mercury lamp, where the cladding material 3 covering the outer periphery is subjected to a crosslinking reaction, and then sent into a heating furnace 6, where the core material 2 is subjected to a crosslinking reaction. let

The optical fiber 1 which has been cross-linked as described above has its outer diameter measured by a laser outer diameter measuring device 7, which is an outer diameter measuring member, and then passed through an auxiliary roller 8 and then fixed to the optical fiber 1 by a tension roller 9. The rubber-like elastic optical fiber 1 is continuously manufactured by winding it up by the winding machine 10 with the tension applied thereto.

Here, the outer diameter size signal of the optical fiber 1 measured by the laser outer diameter measuring device 7 is sent to the control member 11, and the control member 1l controls the optical fiber 1 before being wound into the winder 10. 1, said tension roller 9 acting on
The tension can be controlled.

The control member 1l further controls the winding machine 1.
It is possible to control the winding speed of 0.

Further, the winder 10 is provided with a guide part 12 for smooth winding of the optical fiber 1, and further, an outer diameter display part 13 is connected to the control member 11, It is possible to directly read the outer diameter dimension of the optical fiber l during the manufacturing process, which is measured by the laser outer diameter measuring device 7.

In the manufacturing method of the present invention, prior to continuous manufacturing, the outer diameter of the optical fiber 1 is determined while the winder 10 is winding the optical fiber 1 at a constant winding speed. The tension acting on the optical fiber 1 of the tension roller 9 is adjusted to a predetermined value by the control member 11 so that the outer diameter dimension signal measured by the laser outer diameter measuring device 7 becomes a signal corresponding to the desired outer diameter. Decide on the value.

Specifically, when the outer diameter dimension is smaller than the target outer diameter value, the control member 11 sets the tension a acting on the optical holder 1 of the tension roller 9 to be small, and the crosslinking process is performed. At a stage before the crosslinking process is applied, the optical fiber 1 of a desired diameter is formed and sent to the next crosslinking process.

Further, when the outer diameter is larger than the target outer diameter value, the control member 11 sets the tensigon acting on the tensigon roller 9 to a large value, and the desired diameter is set before the crosslinking treatment is performed. The optical fiber 1 is then sent to the next crosslinking process.

After that, the control member 11 controls the optical fiber 1.
The winding speed of the winder 10 is controlled so as to keep the tension of the tension roller 9 constant, and the winder 10 continuously winds the optical fiber 1.

Therefore, in the present invention configured as described above,
The optical fiber 1 of the tension roller 9 is controlled by the control member 11 according to the outer diameter dimension measured by the laser outer diameter measuring device 7.
The winding speed of the winding machine 10 is controlled to keep the set tension constant, so that the rubber-like elastic optical fiber 1 having a constant outer diameter is continuously manufactured. It is possible.

As a result, even if, for example, the optical fibers 1 wound by the winder 10 overlap and the amount of winding per rotation changes, the tension acting on the optical fiber 1 of the tension roller 9 is kept constant. Furthermore, even if the core material 2 and the crund material 3 have slightly different physical properties depending on the lot, the control member 11 allows the optical fiber 1 to be manufactured with a constant diameter at the setting stage. Since the tension of the tension roller 9 acting on the optical fiber 1 can be changed, it is possible to manufacture an optical fiber 1 having a constant outer diameter without being affected by the lot.

The core material 2 of the optical fiber 1 may be any material as long as it has excellent transparency and becomes a rubber-like elastic body when crosslinked by heating. For example, acrylic rubber, silicone rubber, etc. may be crosslinked in an appropriate amount. Examples include polymeric materials to which agents and the like are added.

The cladding material 3 of the optical fiber 1 has poor transparency, has a refractive index 2% or more lower than the core material 2, and is easily crosslinked (in a short period of time) by heating or radiation (ultraviolet rays, electron beams, etc.). Any material may be used as long as it forms a rubber-like elastic body; for example, a copolymer of octafluoropentyl acrylate-1- (hereinafter abbreviated as ○FPA) and dicyclopentenyl acrylate (hereinafter abbreviated as DCPA) Combination, Te1 lafluoroprobyl acrylate (
Examples include copolymers of 2-hydroxyethyl acrylate (hereinafter referred to as TFPA) and 2-hydroxyethyl acrylate (hereinafter referred to as HEA), and polymeric materials in which appropriate amounts of photopolymerization initiators, crosslinking aids, etc. are added to dimethyl silicone, etc. It will be done.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

As the core material 2, a copolymer of ethyl acrylate (hereinafter abbreviated as EA) and HEA (molar ratio 96:4, refractive index nD2S = 1.480), and three amounts of hexamethylene diisocyanate as a crosslinking material. A copolymer was used in which hydroxyl groups (10H) and isocyanate groups (100N) were added in amounts such that OCN/OH=1.1.

As the cladding material 3, a copolymer of FPA and DCPA (molar ratio 90:10, refractive index n,″-1.386) 10
0 part, 0.5 part of 2-hydroxy-2-methyl-1-phenylpropan-1-one (hereinafter abbreviated as HMP P) (Darocur 1173, manufactured by Merck Japan) as a polymerization initiator, and 0.5 part as a crosslinking aid. A solution containing 10 parts of tetraethylene glycol diacrylate (hereinafter abbreviated as TEGDA) was used.

Three lots of each of the core material 2 and cladding material 3 were prepared, and the physical properties of the number average molecular weight (expressed as Mn), weight average molecular weight (expressed as Mw), and extrusion viscosity for each loft were measured.

Molecular weight distribution number is measured by gel permeation chromatography method, and extrusion viscosity is measured using Flow Tester CF.
T-500 (manufactured by Shimadzu Corporation) diameter 1 mm
Measurements were made using a 5 mm die.

The results are shown in Table 1 below.

[Margin below]

12 Table-1 Loft No. Average molecular weight Mn Mw Extrusion viscosity (poise) Core 8.6 ×lO' 1.8 XIO54.2X1
0'■ Craft 7.1 XIO' 1. O
XIO'2.6X10' Core 8.8 XIO
'1. O X105 4.3X10' ■Craft
7.1 x 10' 1.2 x 10'
2.7 x 10' core 8.9 XIO' 1.9
XIO54.5X10'■Craft 7.2 X
IO' 1.3 Rubber-like elastic optical fiber 1 was manufactured using T, ■ and ■ as follows.

Manufacturing Example-1 Using the apparatus shown in FIGS. 1 and 2, the core material 2 of Lot No.
and cladding material 3 were coextruded.

Then, the extruded material is sent into a lamp house 5 (lamp irradiation distance 10 cm, lamp irradiation length 5 crn) having two 800W high-pressure mercury lamps (manufactured by Toshiba Denzai Co., Ltd.) to crosslink the cladding material 3, and further, The core material 2 is crosslinked by passing through a heating furnace 6 at 120°C.

Then, the outer diameter dimension of the crosslinked optical fiber 1 is measured by the laser outer diameter measuring device 7, and the outer diameter dimension signal is sent to the control member 1l.

The control member 11 controls the tension roller 9 to apply a predetermined tension to the optical fiber 1 according to the outer diameter dimension signal, and further controls the winding so that the tension of the tension roller 9 is kept constant. A signal is issued to control the winding speed of a10.

At this time, the initial outer diameter dimension setting value is 1.0 mm,
The control member 11 sets the tension acting on the optical fiber 1 of the tension roller 9, and controls the winding speed of the winder 10 so as to keep the set tension constant. Rubber-like elastic optical fiber 1 was manufactured by continuously winding it.

In addition, a laser outer diameter measuring device 7 (LS-30 manufactured by Keyence Corporation)
30), the outer diameter dimension before crosslinking and the outer diameter dimension after crosslinking immediately after extrusion of the optical fiber 1 in the manufacturing process were measured.

The optical fiber 1 obtained in Section 7 was used as sample No. It shall be 1.

Production Example-2 In Production Example-1 described in -1-, the Ronoto No.
Lot No. 1 instead of Lot No. 1. Rubber-like elastic optical fiber 1 was obtained in the same manner except that H was used. This optical fiber 1 was used as sample No. Set it to 2.

Production Example-3 In the above Production Example-1, the lot I-No. 1
In place of 15, Rosoto No. Rubber-like elastic optical fiber 1 was obtained in the same manner except that III was used. This optical fiber 1
Sample No. Set it to 3.

Manufacturing Example-4 In Manufacturing Example-1 of L, the outer diameter 1 method to be set is 0.9
Rubber-like elastic optical fiber 1 was obtained in the same manner except that the thickness was changed to mm. This optical fiber 1 was used as sample No. Set it to 4.

Production Example 5 (Comparative Example) A rubber-like elastic optical fiber 1 was obtained in the same manner as in Production Example 1 above, except that the control member 11 and the tension roller 9 were not used. This optical fiber 1 was used as sample No. 5(
comparison).

Production Example 6 (Comparative Example) Rubber-like elastic optical fiber 1 was obtained in the same manner as in Production Example 4 above, except that the control member 11 and the tension roller 9 were not used. This optical fiber l was used as sample No. 6(
comparison).

The data of the outer diameter dimension immediately after extrusion and the outer diameter dimension I6 after crosslinking of samples No. 1 to 6 obtained in Production Examples 1 to 6 described in "2" are shown in Table 2 below, respectively.

Sample No. Usage Port No. 1 Application 2 Application 3 Application 4 Application 5 Comparison 6 Comparison ■ n ■ Table 2 Diameter immediately after extrusion Diameter after crosslinking (mm) (mm) 1.20±0.01 1.00 ±0.01 1.22±0.01 1.00 ±0.01 1.23±0.01 1.00 ±0.01 1 (0.9) 1.15±0.01■ 1. l9±0.11 1 (0.9) 1.13±0.090.90 ±
0.01 0.94 ±0.08 0.81 ±0.06 As is clear from the results in Table 2, sample No. 5 obtained in comparative manufacturing examples-5 and 6 without using a control member and tension roller ．． In contrast to No. 5 and No. 6, the variation in the outer diameter of the obtained optical fiber is large and it is not possible to obtain a predetermined outer diameter, whereas in the present invention,
It can be seen that even if the set dimensions are changed, the variation in the outer diameter of the optical fiber obtained is small, and that the outer diameter of the optical fiber is a predetermined value.

〔Effect of the invention〕

Since the present invention is constructed as described above, it has the advantageous effects of being able to continuously manufacture rubber-like elastic optical fibers having small variations in outer diameter dimensions and having a predetermined outer diameter dimension. It is something that you have.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram illustrating a method for manufacturing an optical fiber according to the present invention, and FIG. 2 is an explanatory diagram of the main part of FIG. 1. l... Optical fiber 2... Core material 3... Clad material 4... Double concentric extrusion nozzle 5...
Lamp house 6... Heating furnace 7... Laser outer diameter measuring device (outer diameter measuring member) 8... Auxiliary roller 9... Tension roller 10... ... Winder 1l ... Control member 12 ... Guide member 13 ... Outer diameter display section patent application filed by NOK Co., Ltd.

Claims (1)

[Claims] (1) Obtained by extruding a rubber core material (2) from a double concentric extrusion nozzle (4) and simultaneously extruding a rubber cladding material (3) covering its outer periphery and subjecting it to crosslinking treatment. Winder (10) for winding optical fiber (1)
), the method comprises: winding the optical fiber (1) with a winder (10) driven by a control member (11) at a predetermined winding speed; At the same time, the control member (11) operates the tension roller (9) to tighten the optical fiber (1).
A predetermined tension is applied to the control member (11) so that the measured value of the outer diameter measuring member (7) that measures the outer diameter of the optical fiber (1) becomes a desired outer diameter dimension.
controls the tension roller (9) to determine the tension acting on the optical fiber (1), and then controls the control member (11) to maintain the determined tension.
controls the winding speed of the winder (10).